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47-450: El Chichón became famous for its 1982 eruption. In little under a week, the presumed dormant volcano produced three plinian eruptions (March 29, April 3, and April 4). The eruptions released a substantial amount of sulfur dioxide and particulates into the atmosphere. While the total volume of the eruption was much smaller than the famous eruption of Pinatubo in 1991, El Chichón's impacts were equally significant on global climate. El Chichón

94-404: A better sight of this very uncommon appearance. A cloud, from which mountain was uncertain, at this distance (but it was found afterwards to come from Mount Vesuvius), was ascending, the appearance of which I cannot give you a more exact description of than by likening it to that of a pine tree, for it shot up to a great height in the form of a very tall trunk, which spread itself out at the top into

141-435: A correct description of the source of stratospheric ozone and its ability to generate heat within the stratosphere; he also wrote that ozone may be destroyed by reacting with atomic oxygen, making two molecules of molecular oxygen. We now know that there are additional ozone loss mechanisms and that these mechanisms are catalytic, meaning that a small amount of the catalyst can destroy a great number of ozone molecules. The first

188-428: A cutoff for an ultra-Plinian eruption. In the criteria of Volcanic Explosivity Index , recognizing an eruption as ultra-Plinian would make it at least VEI-5 or higher. The threshold for ultra-Plinian eruptions is defined by an eruptive column height of 45 km (28 mi), or 41 km (25 mi) more recently. The few instances of eruptions that lie at the transition between Plinian and ultra-Plinian include

235-609: A man of such learning and research as my uncle extraordinary and worth further looking into. Pliny the Elder set out to rescue the victims from their perilous position on the shore of the Bay of Naples , and launched his galleys , crossing the bay to Stabiae (near the modern town of Castellammare di Stabia). Pliny the Younger provided an account of his death, and suggested that he collapsed and died through inhaling poisonous gases emitted from

282-484: A phenomenon called Rossby-wave pumping. An interesting feature of stratospheric circulation is the quasi-biennial oscillation (QBO) in the tropical latitudes, which is driven by gravity waves that are convectively generated in the troposphere . The QBO induces a secondary circulation that is important for the global stratospheric transport of tracers, such as ozone or water vapor . Another large-scale feature that significantly influences stratospheric circulation

329-412: A sort of branches; occasioned, I imagine, either by a sudden gust of air that impelled it, the force of which decreased as it advanced upwards, or the cloud itself being pressed back again by its own weight, expanded in the manner I have mentioned; it appeared sometimes bright and sometimes dark and spotted, according as it was either more or less impregnated with earth and cinders. This phenomenon seemed to

376-527: A volcanic event would induce global cooling, particularly in summer months, however no cooling was seen in the first year after the El Chichón eruption, because the El Niño produced large compensating warming. The climatic effects also triggered winter warming patterns observed within northern hemisphere continents in 1982 and 1983, with temperatures increasing over North America, Europe, and Siberia. During

423-401: Is caused by variations in the jet stream and other local wind shears, although areas of significant convective activity ( thunderstorms ) in the troposphere below may produce turbulence as a result of convective overshoot . On October 24, 2014, Alan Eustace became the record holder for reaching the altitude record for a manned balloon at 135,890 ft (41,419 m). Eustace also broke

470-521: Is due to the reaction of hydroxyl radicals (•OH) with ozone. •OH is formed by the reaction of electrically excited oxygen atoms produced by ozone photolysis, with water vapor. While the stratosphere is dry, additional water vapor is produced in situ by the photochemical oxidation of methane (CH 4 ). The HO 2 radical produced by the reaction of OH with O 3 is recycled to OH by reaction with oxygen atoms or ozone. In addition, solar proton events can significantly affect ozone levels via radiolysis with

517-513: Is often overlooked in comparison to other historic eruptions, yet the 1982 eruptions provide important lessons on preparation for volcanic disasters and the influence volcanoes can have on climate. The 1982 eruption of El Chichón is the largest volcanic disaster in modern Mexican history. The powerful 1982 explosive eruptions of high-sulfur, anhydrite-bearing magma destroyed the summit lava dome and were accompanied by pyroclastic flows and surges that devastated an area extending about 8 km around

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564-413: Is problematic, since ash samples are collected from the ground in order for the optical and chemical properties to be measured which too will vary with distance from the volcano. Therefore, one can only measure certain relevant parameters for samples collected from the air or from the ground. However, some samples are of greater interest than others. Thus, the most important samples are the ones furthest from

611-487: Is the breaking planetary waves resulting in intense quasi-horizontal mixing in the midlatitudes. This breaking is much more pronounced in the winter hemisphere where this region is called the surf zone. This breaking is caused due to a highly non-linear interaction between the vertically propagating planetary waves and the isolated high potential vorticity region known as the polar vortex . The resultant breaking causes large-scale mixing of air and other trace gases throughout

658-412: Is usually dacitic or rhyolitic , rich in silica. Basaltic , low-silica lavas rarely produce Plinian eruptions unless specific conditions are met (low magma water content <2%, moderate temperature, and rapid crystallization); a recent basaltic example is the 1886 eruption of Mount Tarawera on New Zealand's North Island . Pliny the Younger described the initial observations of his uncle, Pliny

705-641: The P3 phase of 1257 Samalas eruption , 1991 eruption of Mount Pinatubo , the Plinian phase of the Campanian Ignimbrite , Tsankawi Pumice Bed of Tshirege Member of Bandelier Tuff , and the 1902 eruption of Santa María . The once unequivocal ultra-Plinian classification of the Hatepe eruption has been called into question, with recent evidence showing that it is an artifact of an unrecognized shift in

752-604: The UV-C region, at wavelengths shorter than about 240 nm. Radicals produced from the homolytically split oxygen molecules combine with molecular oxygen to form ozone. Ozone in turn is photolysed much more rapidly than molecular oxygen as it has a stronger absorption that occurs at longer wavelengths, where the solar emission is more intense. Ozone (O 3 ) photolysis produces O and O 2 . The oxygen atom product combines with atmospheric molecular oxygen to reform O 3 , releasing heat. The rapid photolysis and reformation of ozone heat

799-474: The 1982 eruption is believed to amount to $ 55 million (equivalent to $ 132 million in present-day US dollars). With more than 600 years since the last major eruption of El Chichón, few people were aware of the volcanic risk. Most presumed it to be a dormant volcano or extinct. Throughout 1980 and 1981 earthquakes were felt in the surrounding regions, and geologists hazard mapped the region highlighting risks, but no increases were seen in monitoring activity. It

846-415: The El Chichón cloud, the optical depth has been measured to be around 0.3 around mid-visible wavelengths. The imaginary part of the refractive index , describing the attenuation of radiation for the 80 km sample, varies between 0.004 at 300 nm and 0.001 at 700 nm. Based on these results, the real part of the refractive index of the stratospheric El Chichón ash is estimated around 1.52, while

893-409: The El Chichón eruption caused the El Niño. However, climate modeling and detailed studies of past eruptions and El Niño have shown that there are no plausible theories connecting these two events, and that the timing was merely a coincidence. As a result of the simultaneous eruption and El Niño, the climate felt the impacts of both, making it challenging to separate their effects on temperature. Generally

940-404: The Elder , of the 79 AD eruption of Mount Vesuvius : On August 24th, about one in the afternoon, my mother desired him to observe a cloud which appeared of a very unusual size and shape. He had just taken a turn in the sun and, after bathing himself in cold water, and making a light luncheon, gone back to his books: he immediately arose and went out upon a rising ground from whence he might get

987-402: The altitudes of normal lightning and storm clouds. Upper-atmospheric lightning is believed to be electrically induced forms of luminous plasma . Lightning extending above the troposphere into the stratosphere is referred to as blue jet , and that reaching into the mesosphere as red sprite . Bacterial life survives in the stratosphere, making it a part of the biosphere . In 2001, dust

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1034-489: The cold European winters of the 1960s. Stratospheric warming of the polar vortex results in its weakening. When the vortex is strong, it keeps the cold, high-pressure air masses contained in the Arctic ; when the vortex weakens, air masses move equatorward, and results in rapid changes of weather in the mid latitudes. Upper-atmospheric lightning is a family of short-lived electrical-breakdown phenomena that occur well above

1081-519: The cooler layers lower (closer to the planetary surface of the Earth). The increase of temperature with altitude is a result of the absorption of the Sun 's ultraviolet (UV) radiation by the ozone layer , where ozone is exothermically photolyzed into oxygen in a cyclical fashion . This temperature inversion is in contrast to the troposphere, where temperature decreases with altitude, and between

1128-604: The death of his uncle Pliny the Elder . Plinian/Vesuvian eruptions are marked by columns of volcanic debris and hot gases ejected high into the stratosphere , the second layer of Earth's atmosphere. The key characteristics are the ejection of a large amount of pumice and very powerful continuous gas-driven eruptions. Short eruptions can end in less than a day, but longer events can continue for several days or months. The longer eruptions begin with production of clouds of volcanic ash, sometimes with pyroclastic surges . The amount of magma ejected can be so large that it depletes

1175-533: The discovery of an isothermal layer at around 11–14 km (6.8-8.7 mi), which is the base of the lower stratosphere. This was based on temperature profiles from mostly unmanned and a few manned instrumented balloons. The mechanism describing the formation of the ozone layer was described by British mathematician and geophysicist Sydney Chapman in 1930, and is known as the Chapman cycle or ozone–oxygen cycle . Molecular oxygen absorbs high energy sunlight in

1222-411: The imaginary part is expected to be slightly less than the one measured for the ground samples. Plinian Plinian eruptions or Vesuvian eruptions are volcanic eruptions marked by their similarity to the eruption of Mount Vesuvius in 79 AD , which destroyed the ancient Roman cities of Herculaneum and Pompeii . The eruption was described in a letter written by Pliny the Younger , after

1269-566: The lift by the lift-to-drag ratio .) It also allows the airplane to stay above the turbulent weather of the troposphere. The Concorde aircraft cruised at Mach 2 at about 60,000 ft (18 km), and the SR-71 cruised at Mach 3 at 85,000 ft (26 km), all within the stratosphere. Because the temperature in the tropopause and lower stratosphere is largely constant with increasing altitude, very little convection and its resultant turbulence occurs there. Most turbulence at this altitude

1316-406: The lower reaches of the stratosphere in temperate latitudes. This optimizes fuel efficiency , mostly due to the low temperatures encountered near the tropopause and low air density, reducing parasitic drag on the airframe . Stated another way, it allows the airliner to fly faster while maintaining lift equal to the weight of the plane. (The fuel consumption depends on the drag, which is related to

1363-600: The magma chamber below, causing the top of the volcano to collapse, resulting in a caldera . Fine ash and pulverized pumice can be deposited over large areas. Plinian eruptions are often accompanied by loud sounds. The sudden discharge of electrical charges accumulated in the air around the ascending column of volcanic ashes also often causes lightning strikes, as depicted by the English geologist George Julius Poulett Scrope in his painting of 1822 or observed during 2022 Hunga Tonga–Hunga Ha'apai eruption and tsunami . The lava

1410-492: The midlatitude surf zone. The timescale of this rapid mixing is much smaller than the much slower timescales of upwelling in the tropics and downwelling in the extratropics. During northern hemispheric winters, sudden stratospheric warmings , caused by the absorption of Rossby waves in the stratosphere, can be observed in approximately half of winters when easterly winds develop in the stratosphere. These events often precede unusual winter weather and may even be responsible for

1457-438: The ozone layer allows life to exist on the surface of the planet outside of the ocean. All air entering the stratosphere must pass through the tropopause , the temperature minimum that divides the troposphere and stratosphere. The rising air is literally freeze dried; the stratosphere is a very dry place. The top of the stratosphere is called the stratopause , above which the temperature decreases with height. Sydney Chapman gave

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1504-671: The same winter, Alaska, Greenland, the Middle East, and China witnessed colder temperatures than normal, highlighting regional variation. The variation is said to be a result of volcanic aerosols impact on the atmospheric wind patterns, including the Arctic Oscillation. The westerly drift of the El Chichon eruption cloud had significant impact on Hong Kong's 1982 annual rainfall causing the second wettest year (3247.5mm) since record began in 1884. Satellite tracking showed

1551-432: The stratosphere dynamically stable: there is no regular convection and associated turbulence in this part of the atmosphere. However, exceptionally energetic convection processes, such as volcanic eruption columns and overshooting tops in severe supercell thunderstorms , may carry convection into the stratosphere on a very local and temporary basis. Overall, the attenuation of solar UV at wavelengths that damage DNA by

1598-432: The stratosphere is termed as Brewer-Dobson circulation , which is a single-celled circulation, spanning from the tropics up to the poles, consisting of the tropical upwelling of air from the tropical troposphere and the extra-tropical downwelling of air. Stratospheric circulation is a predominantly wave-driven circulation in that the tropical upwelling is induced by the wave force by the westward propagating Rossby waves , in

1645-470: The stratosphere, resulting in a temperature inversion. This increase of temperature with altitude is characteristic of the stratosphere; its resistance to vertical mixing means that it is stratified. Within the stratosphere temperatures increase with altitude (see temperature inversion ) ; the top of the stratosphere has a temperature of about 270 K (−3 °C or 26.6 °F ). This vertical stratification , with warmer layers above and cooler layers below, makes

1692-416: The stratospheric cloud was above Hong Kong on 16 April 1982 which coincided with the record low humidity measured at ground level. Condensation nuclei for rain was provided by aerosols, ice crystals and particulates generated by the eruption settling through the troposphere. The deposition of ash in the surroundings of the volcano varies with distance from the volcano since the ash particles vary in size. This

1739-424: The subsequent formation of OH. Nitrous oxide (N 2 O) is produced by biological activity at the surface and is oxidised to NO in the stratosphere; the so-called NO x radical cycles also deplete stratospheric ozone. Finally, chlorofluorocarbon molecules are photolysed in the stratosphere releasing chlorine atoms that react with ozone giving ClO and O 2 . The chlorine atoms are recycled when ClO reacts with O in

1786-636: The tropopause to an average of −15 °C (5.0 °F; 260 K) near the mesosphere. Stratospheric temperatures also vary within the stratosphere as the seasons change, reaching particularly low temperatures in the polar night (winter). Winds in the stratosphere can far exceed those in the troposphere, reaching near 60 m/s (220 km/h; 130 mph) in the Southern polar vortex . In 1902, Léon Teisserenc de Bort from France and Richard Assmann from Germany, in separate but coordinated publications and following years of observations, published

1833-445: The troposphere and stratosphere is the tropopause border that demarcates the beginning of the temperature inversion. Near the equator , the lower edge of the stratosphere is as high as 20 km (66,000 ft; 12 mi), at mid-latitudes around 10 km (33,000 ft; 6.2 mi), and at the poles about 7 km (23,000 ft; 4.3 mi). Temperatures range from an average of −51 °C (−60 °F; 220 K) near

1880-573: The upper stratosphere, or when ClO reacts with itself in the chemistry of the Antarctic ozone hole. Paul J. Crutzen, Mario J. Molina and F. Sherwood Rowland were awarded the Nobel Prize in Chemistry in 1995 for their work describing the formation and decomposition of stratospheric ozone. Commercial airliners typically cruise at altitudes of 9–12 km (30,000–39,000 ft) which is in

1927-724: The volcano (80 km, 100 km,) due to the fact that they are the most likely to reach the stratosphere . In particular, the 80 km one has shown similarities with stratospheric ash samples. For ash samples around 100 km away from the volcano, the presence of the soluble and non soluble components has been identified. The water-soluble components present in the highest concentration are Ca and SO 4 . There have also been traces of Na , K , Mg , HCO 3 and Cl . The non-soluble part consists mostly of SiO 2 (around 59%) and Al 2 O 3 (around 18%) along with trace amounts (less than 5%) of other components, such as CaO , Na 2 O and Fe 2 O 3 . For

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1974-561: The volcano. A total of 9 villages were completely destroyed, killing 1,900 people. A new 1-km-wide, 300-m-deep crater that now contains an acidic crater lake was created. The landscape was covered in ash up to 40 cm in depth. Over 24,000 km of countryside was affected, devastating coffee, cocoa, banana crops, and cattle ranches. The eruption caused natural dams to form along the Rio Magdalena river, inducing lahars , which destroyed key infrastructure. The total damage caused by

2021-478: The volcano. His body was found interred under the ashes of the eruption with no apparent injuries on 26 August, after the plume had dispersed, confirming asphyxiation or poisoning. In 1980, volcanologist George P. L. Walker proposed Hatepe eruption as the representative of a new class called ultra-Plinian deposits, based on its exceptional dispersive power and eruptive column height. A dispersal index of 50,000 square kilometres (19,000 sq mi) has been proposed as

2068-417: The wind field rather than extreme eruptive vigor. Stratosphere The stratosphere ( / ˈ s t r æ t ə ˌ s f ɪər , - t oʊ -/ ) is the second-lowest layer of the atmosphere of Earth , located above the troposphere and below the mesosphere . The stratosphere is composed of stratified temperature zones, with the warmer layers of air located higher (closer to outer space ) and

2115-456: The world records for vertical speed skydiving, reached with a peak velocity of 1,321 km/h (822 mph) and total freefall distance of 123,414 ft (37,617 m) – lasting four minutes and 27 seconds. The stratosphere is a region of intense interactions among radiative, dynamical , and chemical processes, in which the horizontal mixing of gaseous components proceeds much more rapidly than does vertical mixing. The overall circulation of

2162-492: Was a VEI-5 eruption, injecting 7 million metric tonnes of sulfur dioxide and 20 million metric tonnes total of particulate material into the stratosphere , which circulated the Earth in three weeks. The amount of sulfur dioxide is comparable to the 20 million tonnes of the 1991 eruption of Mount Pinatubo . The eruption occurred just as the 1982–83 El Niño event was initiating; because of this several scientists suggested that

2209-550: Was collected at a height of 41 kilometres in a high-altitude balloon experiment and was found to contain bacterial material when examined later in the laboratory. Some bird species have been reported to fly at the upper levels of the troposphere. On November 29, 1973, a Rüppell's vulture ( Gyps rueppelli ) was ingested into a jet engine 11,278 m (37,000 ft) above the Ivory Coast . Bar-headed geese ( Anser indicus ) sometimes migrate over Mount Everest , whose summit

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